人脑胶质瘤细胞SHG-44照射后COX-2表达与放射敏感性的关系

Relationship between of COX-2 expression and radiosensitivity of the irradiated human glioma SHG-44 cells

目的:探讨人脑胶质瘤细胞SHG-44照射存活后代细胞对放射敏感性的变化,以及环氧合酶-2(COX-2)的表达情况,为临床使用COX-2抑制剂提供理论依据。方法:采用克隆形成率研究SHG-44及SHG-44照射存活后代细胞的放射敏感性;并分别用RT-PCR方法及免疫组化的方法检测COX-2基因mRNA和蛋白的表达情况。结果:与SHG-44细胞相比,SHG-44照射后代细胞对放射的敏感性下降,COX-2 mRNA及蛋白表达均升高。COX-2表达水平与SHG-44照射后代细胞放射敏感性呈负相关。结论:辐射诱导了SHG-44细胞COX-2表达的升高,使SHG-44照射后代细胞对放射敏感性下降,COX-2表达的升高可能是导致其辐射耐受的原因之一。

Objective ： To investigate the changes of radiosensitivity and the expression of cyclooxygenase 2 （ COX-2 ） in the surviving progeny from the irradiated human glioma SHG-44 cells and to provide a theoretical basis for application of COX-2 inhibitors in clinic. Methods： Radiosensitivity of mother SHG-44 cells and that of surviving progeny from the irradiated human glioma SHG-44 cells were studied by measuring the colony-forming rate. The mRNA transcription and protein expression of COX-2 were detected by RT-PCR and immunohistochemical staining, respectively. Results： The radiosensitivity was decreased and the mRNA and protein expressions of COX-2 increased in the surviving progeny of the irradiated SHG-44 cells compared with mother SHG-44 cells. The expression levels of COX-2 were negatively correlated with the radiosensitivity in the irradiated SHG-44 cells. Conclusion： Radiation induced upregulation of COX-2 expression and downregulation of the radiosensitivity in the the surviving progeny from the irradiated human glioma SHG-44 cells. The elevated expression of COX-2 may be one of the reasons for the radioresistance of irradiated SHG-44 cells.